Odor improvement of petroleum resins with vanillin



United States Patent Oil-ice 2,857,361 Patented Oct. 21, 1958 William P.Fitz Gerald, Florham Park, Joseph F. Nelson, Westfield, and Ob'er C.Slotterbeck, .Rahway, N. (1., assignors to Esso Research and EngineeringCompany, a corporation ofDelaware No Drawing. pplication October 14,1954 Serial No. 462,374

3 "Claims. (Cl. 260-4535) This invention relates to a method fordeodorizing petroleum resins and relates more particularly to apetroleum resin composition which contains an odor masking agent.

The preparation of resins by Friedel-Crafts polymerization of steamcracked petroleum fractions is well known. Such resins when freshlyprepared are solid, light colored, and they possess a mild and generallyacceptable odor. preparation of paints and they find application asblending agents with other resins, natural and synthetic rubber, as wellas paper impregnants and many other uses. However, when these resins arestored for any length of time an undesirable burnt" peroxidized odordevelops particularly when the resins are in flake form. Such odordevelopment also occurs when the resin is melted for application topaper or paper board and the like.

According to the present invention the development of this burntperoxidized odor is substantially completely overcome by the addition tothe resin of a small They are commercially useful in the 2 diolefins, to62% olefins, 0-36% aromatics, an 1 to 15% paraffins and naphthenes. Atypical stream shows 20% diolefins, 51% olefins, 27% aromatics, and 2%parafiins and naphthenes. The preparation of these hydrocarbon resins isfurther described in co-pending patent application Serial No. 295,836,filed June 26, 1952, now Patent No. 2,698,841.

According to the preferred method of carrying out the invention, 0.02 to1.0 wt. percent (preferably 0.05%) of vanillin is added to a hydrocarbonresin. As a result of this addition the odor of the resin is overcomeand the mixture has substantially no odor or only a faint trace ofvanillin odor. If antioxidants such as butyl hydroxy anisole are addedthe odor is even further reduced and practically disappears, even at 110C., when butyl hydroxy anisole is used. The presence of 005-2 wt.percent antioxidant is effective.

The following example illustrates the benefits to be secured inaccordance with the present invention:

Example I 30 were prepared. Paper strips were coated by immersion in theresin solutions. These test strips were dried in air and aged for 24hours at 110 F. and then rated by a panel of three members according toa standard odor scale. The following results were obtained:

Ratings Masking A ent Panel Panel Panel Average Sample g Member #1Member #2 Member #3 1 Vanillin.-. 2 Unobjech. 1 Unob]ect 1 Unobject 1-3Unobject, 6 N0ne.- 0-8 Resin Odor.

Code: 1-2-Very faint odor; 3-4-Falnt odor; 5-6Moderate odor; 7-8-Strongodor;

910Very strong odor.

methods, such as addition of methyl alcohol and subsequent filtration,water and/or caustic washing and the final solution is then stripped ofunreacted hydrocarbons and low molecular weight oils by vacuum and/orsteam distillation. The product is a substantially non-aromaticunsaturated hydrocarbon resin. A hydrocarbon mixture suitable for resinproduction is conveniently found in hydrocarbon streams obtained bysteam cracking gas oils. These streams have boiling ranges between 20and 280 C., or may be composed of any intermediate fractions thereof.Preferred streams contain about 12 to The above data clearly show thatvanillin is outstanding in completely masking out the resin odor, thefaint residual odor of vanillin itself being unobjectionablc. In allother cases the odor of the resin was present to an obiectionabledegree. For instance, when no masking agent was used, an odor intensityof 6-8 was noticeable, and when other commercially available maskingagents were used, the intensity varied from about 4 to 9.

Example II Using resin from the same source as described in Example I,the following blends of resin, masking agent, and antioxidant wereprepared:

Sample Masking Percent Percent N 0. Agent Antioxidant Masking Antiox.

Agent 1 vanillin.. Phenothiazine .05 .2 4 do Butylhydroxy Anisole- .05.2 7 None None .05 .2

These blends were heated for 5 hours at 350 F. after which paper teststrips were coated with the resin blends by the same procedure outlinedin Example I.

After heating for '24 hoursat 110 F. the following conditions of odorintensity-and type were noted:

The above results clearly show that the presence of butyl hydroxyanisolerenders the resin composition -con-' tainingvanillin'practicallyodorless, even at 110 F., indicating thatthfeantioxidant has a synergistic effect on the masking qualities' of thevanillin.

While the present invention is more specifically directed to the maskingoffitheodor from steam-cracked resins, it may also be used to masktheodor from any type of hydrocarbon resin.

The nature of the present inventionv having been thus fully set forthandspecific examples of the same given, what is claimed as. new: and usefuland desirable by Letters Patent are:

1. An odor-stable composition which comprises in admixture a petroleumresin prepared by polymerizing in the presence of a Friedel-Craftscatalyst a steamcracked fraction boiling in the range between 20 and 280C. and consisting essentially of 12 to diolefins, to 62% olefins; and 0to 36%- aromatics, and lto 15% paraflins and naphthenes, said resinnormally tending to develop an undesirable peroxidized odor uponstanding; and 0.02 to 1.0 weight percent of vanillin.

2. The composition of claim 1 wherein 0.05 to 2 weight percent of butylhydroxy anisole is also present. 3. An odor-stable composition whichcomprises in admixture a petroleum resin prepared by polymerizing in thepresence of 0.25 to 2.5% of aluminum chloride a steam-cracked fractionboiling in the range between 20 and 280 C. and consisting essentially of12 to 30% diolefins, 45 to 62% olefins, 0 to 36%. ar omatics, and 1 to15% paraffins. and naphthenes, said resin normally tending to develop anundesirableperoxidized odor upon standing; about 0.05 weight percent ofvanillin; and about 0.2 weight percent of butyl hydroxy anisole.

References Cited in the file ofthis patent UNITED STATES PATENTS2,364,027 Marshall Nov. 28, 1944 2,683,132 Young et a1. July 6, 19542,698,463 Conwell .et al; Jan. 4, 1955 FOREIGN PATENTS 577,875 GreatBritain June 4, 1946 OTHER REFERENCES Foley: Odorants. in Rubber," IndiaRubber World,

' 30 June 1 19.33, pages30 and 39.,

1. AN ODOR-STABLE COMPOSITION WHICH COMPRISES IN ADMIXTURE A PERTOLUMRESIN PREPARED BY POLYMERZING IN THE PRESENCE OF A FRIEDEL-CRAFTSCATALYSYT A STREAMCRACKED FRACTION BOILING IN THE RANGE BETWEEN 20 AND280*C. AND CONSISTING ESSENTIALLY OF 12 TO 30% DIOLEFINS, 45 TO 62%OLEFINS, ND 0 TO 36% AROMATICS, AND 1 TO 15% PARAFFINS AND NAPHTHENES,SAID RESIN NORMALLY TENDING TO DEVEIOP AN UNDESIRABLE PEROXIDIZED ODORUPON STANDING; AND 0.02 TO 1.0 WEIGHT PERCENT OF VANILLIN.